Quality control samples were used in each assay run and demonstrated to be suitable for their intended purpose by consistently performing within the previously established neutralization titer limits, and served to monitor assay performance.
A major limitation in the development of novel HIV-2 diagnostic assays is the lack of reference materials that can be used to evaluate, optimize, and monitor assay performance.
The PC and NC were used to monitor assay performance and verify plate acceptability.
Two negative and one positive control were included to ensure blinding and monitor assay performance.
To monitor assay performance, breast-cancer samples of known ER, PgR or Ki67 content were included as positive controls in every assay.
Each run contained multiple replicates of a reference antiserum pool starting at a 1 32 dilution to monitor assay performance and variation.
All PCR's were run with a negative extraction, as well as negative and positive controls; the latter to monitor assay performance across runs.
An important step towards establishing whether this might be possible in the future would require systematic retrospective analysis using standardized assay conditions, and the identification of suitable positive controls to monitor assay performance.
Acceptance criteria were pre-determined to accept or reject a new lot of reagent before implementation, and the trending of qualified assay quality controls was applied for a continuous monitoring of assay performance over time.
25OHD concentration (DiaSorin, UK; assay performance monitored by DEQAS http://www.deqas.org/), parathyroid hormone (PTH; Immulite, Siemens Healthcare Diagnostics, UK; assay performance monitored by NEQAS http://www.ukneqas.org.uk), 1,25(OH)2D (IDS, UK also DEQAS), calcium, phosphate and albumin (Kone Analyser 20i, Finland) were measured.
Assay performance was monitored following infection of MDCK cells.
